In recent years, the smaller size and increased thinness of mobile phones and other information terminals have led to improvement of their portability and operability. To facilitate viewing of the display, there are products where the display parts and other movable parts are made to slide with respect to the keyboard and other fixed parts. FIG. 1A illustrates an information terminal 3 in the state where a fixed housing (lower housing) 1 has a movable housing (upper housing) 2 laid over it. This information terminal 3, as illustrated in FIG. 1B, is used in a state with the movable housing 2 made to slide with respect to the fixed housing 1. As such a type of information terminal 3, for example, there are mobile phones, handheld terminals (tablet computers and other small-sized computers), game machines, etc.
In this regard, in such an information terminal 3, as illustrated in FIG. 1B, when the movable housing 2 is made to slide with respect to the fixed housing 1, due to the structure of the housing, it is necessary that in the state where the fixed housing 1 and the movable housing 2 are opened up wide (fully slid state), there be a part L where the two are superposed. For this reason, the amount of slide of the movable housing 2 with respect to the fixed housing 1 was up to about two-thirds of the housing length in the slid direction. This structure was good in the case of making the lower fixed housing 1 the keyboard, but when the lower fixed housing 1 is a display part, since there is an overlap part L, a sufficient display area could not be obtained.
As opposed to this, an information terminal 4 of a structure where the movable housing 2 becomes flat with respect to the fixed housing 1 (fully flat) at the time of full sliding such as illustrated in FIG. 1C is, for example, disclosed in Japanese Laid Open Patent Publication No. 2009-71588 and Japanese Laid Open Patent Publication No. 2010-154149. In Japanese Laid Open Patent Publication No. 2009-71588, there are coupling pieces which couple the side surfaces of the fixed housing (first housing) and movable housing (second housing). One of two pins at the coupling pieces is supported at the movable housing in a rotatable state, while the other is engaged with the fixed housing in a slidable state. Further, in Japanese Laid Open Patent Publication No. 2010-154149, a fixed housing (second housing) and a movable housing (first housing) are connected by a link mechanism. The movable housing is slid full from the fixed housing segment resulting in a fully flat display screen.
When using a handheld terminal for applications such as e-mail or Twitter, a small size such as that of a smartphone is good, but when viewing a magazine or newspaper in the form of an electronic book, a large screen tablet is suitable. Further, carrying around both a smartphone type mobile phone and tablet is troublesome, so there is a need for using a tablet for both applications.